crypto/dist/heimdal/appl/ftp/ftpd/gssapi.c

   1 /*
   2  * Copyright (c) 1998 - 2005 Kungliga Tekniska Högskolan
   3  * (Royal Institute of Technology, Stockholm, Sweden).
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  *
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  *
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  *
  17  * 3. Neither the name of the Institute nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #ifdef FTP_SERVER
  35 #include "ftpd_locl.h"
  36 #else
  37 #include "ftp_locl.h"
  38 #endif
  39 #include <gssapi.h>
  40 #include <krb5_err.h>
  41
  42 __RCSID("$Heimdal: gssapi.c 21513 2007-07-12 12:45:25Z lha $"
  43         "$NetBSD$");
  44
  45 int ftp_do_gss_bindings = 0;
  46 int ftp_do_gss_delegate = 1;
  47
  48 struct gss_data {
  49     gss_ctx_id_t context_hdl;
  50     char *client_name;
  51     gss_cred_id_t delegated_cred_handle;
  52     void *mech_data;
  53 };
  54
  55 static int
  56 gss_init(void *app_data)
  57 {
  58     struct gss_data *d = app_data;
  59     d->context_hdl = GSS_C_NO_CONTEXT;
  60     d->delegated_cred_handle = GSS_C_NO_CREDENTIAL;
  61 #if defined(FTP_SERVER)
  62     return 0;
  63 #else
  64     /* XXX Check the gss mechanism; with  gss_indicate_mechs() ? */
  65 #ifdef KRB5
  66     return !use_kerberos;
  67 #else
  68     return 0;
  69 #endif /* KRB5 */
  70 #endif /* FTP_SERVER */
  71 }
  72
  73 static int
  74 gss_check_prot(void *app_data, int level)
  75 {
  76     if(level == prot_confidential)
  77         return -1;
  78     return 0;
  79 }
  80
  81 static int
  82 gss_decode(void *app_data, void *buf, int len, int level)
  83 {
  84     OM_uint32 maj_stat, min_stat;
  85     gss_buffer_desc input, output;
  86     gss_qop_t qop_state;
  87     int conf_state;
  88     struct gss_data *d = app_data;
  89     size_t ret_len;
  90
  91     input.length = len;
  92     input.value = buf;
  93     maj_stat = gss_unwrap (&min_stat,
  94                            d->context_hdl,
  95                            &input,
  96                            &output,
  97                            &conf_state,
  98                            &qop_state);
  99     if(GSS_ERROR(maj_stat))
 100         return -1;
 101     memmove(buf, output.value, output.length);
 102     ret_len = output.length;
 103     gss_release_buffer(&min_stat, &output);
 104     return ret_len;
 105 }
 106
 107 static int
 108 gss_overhead(void *app_data, int level, int len)
 109 {
 110     return 100; /* dunno? */
 111 }
 112
 113
 114 static int
 115 gss_encode(void *app_data, void *from, int length, int level, void **to)
 116 {
 117     OM_uint32 maj_stat, min_stat;
 118     gss_buffer_desc input, output;
 119     int conf_state;
 120     struct gss_data *d = app_data;
 121
 122     input.length = length;
 123     input.value = from;
 124     maj_stat = gss_wrap (&min_stat,
 125                          d->context_hdl,
 126                          level == prot_private,
 127                          GSS_C_QOP_DEFAULT,
 128                          &input,
 129                          &conf_state,
 130                          &output);
 131     *to = output.value;
 132     return output.length;
 133 }
 134
 135 static void
 136 sockaddr_to_gss_address (struct sockaddr *sa,
 137                          OM_uint32 *addr_type,
 138                          gss_buffer_desc *gss_addr)
 139 {
 140     switch (sa->sa_family) {
 141 #ifdef HAVE_IPV6
 142     case AF_INET6 : {
 143         struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sa;
 144
 145         gss_addr->length = 16;
 146         gss_addr->value  = &sin6->sin6_addr;
 147         *addr_type       = GSS_C_AF_INET6;
 148         break;
 149     }
 150 #endif
 151     case AF_INET : {
 152         struct sockaddr_in *sin4 = (struct sockaddr_in *)sa;
 153
 154         gss_addr->length = 4;
 155         gss_addr->value  = &sin4->sin_addr;
 156         *addr_type       = GSS_C_AF_INET;
 157         break;
 158     }
 159     default :
 160         errx (1, "unknown address family %d", sa->sa_family);
 161
 162     }
 163 }
 164
 165 /* end common stuff */
 166
 167 #ifdef FTP_SERVER
 168
 169 static int
 170 gss_adat(void *app_data, void *buf, size_t len)
 171 {
 172     char *p = NULL;
 173     gss_buffer_desc input_token, output_token;
 174     OM_uint32 maj_stat, min_stat;
 175     gss_name_t client_name;
 176     struct gss_data *d = app_data;
 177     gss_channel_bindings_t bindings;
 178
 179     if (ftp_do_gss_bindings) {
 180         bindings = malloc(sizeof(*bindings));
 181         if (bindings == NULL)
 182             errx(1, "out of memory");
 183
 184         sockaddr_to_gss_address (his_addr,
 185                                  &bindings->initiator_addrtype,
 186                                  &bindings->initiator_address);
 187         sockaddr_to_gss_address (ctrl_addr,
 188                                  &bindings->acceptor_addrtype,
 189                                  &bindings->acceptor_address);
 190
 191         bindings->application_data.length = 0;
 192         bindings->application_data.value = NULL;
 193     } else
 194         bindings = GSS_C_NO_CHANNEL_BINDINGS;
 195
 196     input_token.value = buf;
 197     input_token.length = len;
 198
 199     maj_stat = gss_accept_sec_context (&min_stat,
 200                                        &d->context_hdl,
 201                                        GSS_C_NO_CREDENTIAL,
 202                                        &input_token,
 203                                        bindings,
 204                                        &client_name,
 205                                        NULL,
 206                                        &output_token,
 207                                        NULL,
 208                                        NULL,
 209                                        &d->delegated_cred_handle);
 210
 211     if (bindings != GSS_C_NO_CHANNEL_BINDINGS)
 212         free(bindings);
 213
 214     if(output_token.length) {
 215         if(base64_encode(output_token.value, output_token.length, &p) < 0) {
 216             reply(535, "Out of memory base64-encoding.");
 217             return -1;
 218         }
 219         gss_release_buffer(&min_stat, &output_token);
 220     }
 221     if(maj_stat == GSS_S_COMPLETE){
 222         char *name;
 223         gss_buffer_desc export_name;
 224         gss_OID oid;
 225
 226         maj_stat = gss_display_name(&min_stat, client_name,
 227                                     &export_name, &oid);
 228         if(maj_stat != 0) {
 229             reply(500, "Error displaying name");
 230             goto out;
 231         }
 232         /* XXX kerberos */
 233         if(oid != GSS_KRB5_NT_PRINCIPAL_NAME) {
 234             reply(500, "OID not kerberos principal name");
 235             gss_release_buffer(&min_stat, &export_name);
 236             goto out;
 237         }
 238         name = malloc(export_name.length + 1);
 239         if(name == NULL) {
 240             reply(500, "Out of memory");
 241             gss_release_buffer(&min_stat, &export_name);
 242             goto out;
 243         }
 244         memcpy(name, export_name.value, export_name.length);
 245         name[export_name.length] = '\0';
 246         gss_release_buffer(&min_stat, &export_name);
 247         d->client_name = name;
 248         if(p)
 249             reply(235, "ADAT=%s", p);
 250         else
 251             reply(235, "ADAT Complete");
 252         sec_complete = 1;
 253
 254     } else if(maj_stat == GSS_S_CONTINUE_NEEDED) {
 255         if(p)
 256             reply(335, "ADAT=%s", p);
 257         else
 258             reply(335, "OK, need more data");
 259     } else {
 260         OM_uint32 new_stat;
 261         OM_uint32 msg_ctx = 0;
 262         gss_buffer_desc status_string;
 263         gss_display_status(&new_stat,
 264                            min_stat,
 265                            GSS_C_MECH_CODE,
 266                            GSS_C_NO_OID,
 267                            &msg_ctx,
 268                            &status_string);
 269         syslog(LOG_ERR, "gss_accept_sec_context: %s",
 270                (char*)status_string.value);
 271         gss_release_buffer(&new_stat, &status_string);
 272         reply(431, "Security resource unavailable");
 273     }
 274   out:
 275     if (client_name)
 276         gss_release_name(&min_stat, &client_name);
 277     free(p);
 278     return 0;
 279 }
 280
 281 int gss_userok(void*, char*);
 282 int gss_session(void*, char*);
 283
 284 struct sec_server_mech gss_server_mech = {
 285     "GSSAPI",
 286     sizeof(struct gss_data),
 287     gss_init, /* init */
 288     NULL, /* end */
 289     gss_check_prot,
 290     gss_overhead,
 291     gss_encode,
 292     gss_decode,
 293     /* */
 294     NULL,
 295     gss_adat,
 296     NULL, /* pbsz */
 297     NULL, /* ccc */
 298     gss_userok,
 299     gss_session
 300 };
 301
 302 #else /* FTP_SERVER */
 303
 304 extern struct sockaddr *hisctladdr, *myctladdr;
 305
 306 static int
 307 import_name(const char *kname, const char *host, gss_name_t *target_name)
 308 {
 309     OM_uint32 maj_stat, min_stat;
 310     gss_buffer_desc name;
 311     char *str;
 312
 313     name.length = asprintf(&str, "%s@%s", kname, host);
 314     if (str == NULL) {
 315         printf("Out of memory\n");
 316         return AUTH_ERROR;
 317     }
 318     name.value = str;
 319
 320     maj_stat = gss_import_name(&min_stat,
 321                                &name,
 322                                GSS_C_NT_HOSTBASED_SERVICE,
 323                                target_name);
 324     if (GSS_ERROR(maj_stat)) {
 325         OM_uint32 new_stat;
 326         OM_uint32 msg_ctx = 0;
 327         gss_buffer_desc status_string;
 328
 329         gss_display_status(&new_stat,
 330                            min_stat,
 331                            GSS_C_MECH_CODE,
 332                            GSS_C_NO_OID,
 333                            &msg_ctx,
 334                            &status_string);
 335         printf("Error importing name %s: %s\n",
 336                (char *)name.value,
 337                (char *)status_string.value);
 338         free(name.value);
 339         gss_release_buffer(&new_stat, &status_string);
 340         return AUTH_ERROR;
 341     }
 342     free(name.value);
 343     return 0;
 344 }
 345
 346 static int
 347 gss_auth(void *app_data, char *host)
 348 {
 349
 350     OM_uint32 maj_stat, min_stat;
 351     gss_name_t target_name;
 352     gss_buffer_desc input, output_token;
 353     int context_established = 0;
 354     char *p;
 355     int n;
 356     gss_channel_bindings_t bindings;
 357     struct gss_data *d = app_data;
 358     OM_uint32 mech_flags = GSS_C_MUTUAL_FLAG | GSS_C_SEQUENCE_FLAG;
 359
 360     const char *knames[] = { "ftp", "host", NULL }, **kname = knames;
 361
 362
 363     if(import_name(*kname++, host, &target_name))
 364         return AUTH_ERROR;
 365
 366     input.length = 0;
 367     input.value = NULL;
 368
 369     if (ftp_do_gss_bindings) {
 370         bindings = malloc(sizeof(*bindings));
 371         if (bindings == NULL)
 372             errx(1, "out of memory");
 373
 374         sockaddr_to_gss_address (myctladdr,
 375                                  &bindings->initiator_addrtype,
 376                                  &bindings->initiator_address);
 377         sockaddr_to_gss_address (hisctladdr,
 378                                  &bindings->acceptor_addrtype,
 379                                  &bindings->acceptor_address);
 380
 381         bindings->application_data.length = 0;
 382         bindings->application_data.value = NULL;
 383     } else
 384         bindings = GSS_C_NO_CHANNEL_BINDINGS;
 385
 386     if (ftp_do_gss_delegate)
 387         mech_flags |= GSS_C_DELEG_FLAG;
 388
 389     while(!context_established) {
 390         maj_stat = gss_init_sec_context(&min_stat,
 391                                         GSS_C_NO_CREDENTIAL,
 392                                         &d->context_hdl,
 393                                         target_name,
 394                                         GSS_C_NO_OID,
 395                                         mech_flags,
 396                                         0,
 397                                         bindings,
 398                                         &input,
 399                                         NULL,
 400                                         &output_token,
 401                                         NULL,
 402                                         NULL);
 403         if (GSS_ERROR(maj_stat)) {
 404             OM_uint32 new_stat;
 405             OM_uint32 msg_ctx = 0;
 406             gss_buffer_desc status_string;
 407
 408             d->context_hdl = GSS_C_NO_CONTEXT;
 409
 410             gss_release_name(&min_stat, &target_name);
 411
 412             if(*kname != NULL) {
 413
 414                 if(import_name(*kname++, host, &target_name)) {
 415                     if (bindings != GSS_C_NO_CHANNEL_BINDINGS)
 416                         free(bindings);
 417                     return AUTH_ERROR;
 418                 }
 419                 continue;
 420             }
 421
 422             if (bindings != GSS_C_NO_CHANNEL_BINDINGS)
 423                 free(bindings);
 424
 425             gss_display_status(&new_stat,
 426                                min_stat,
 427                                GSS_C_MECH_CODE,
 428                                GSS_C_NO_OID,
 429                                &msg_ctx,
 430                                &status_string);
 431             printf("Error initializing security context: %s\n",
 432                    (char*)status_string.value);
 433             gss_release_buffer(&new_stat, &status_string);
 434             return AUTH_CONTINUE;
 435         }
 436
 437         if (input.value) {
 438             free(input.value);
 439             input.value = NULL;
 440             input.length = 0;
 441         }
 442         if (output_token.length != 0) {
 443             base64_encode(output_token.value, output_token.length, &p);
 444             gss_release_buffer(&min_stat, &output_token);
 445             n = command("ADAT %s", p);
 446             free(p);
 447         }
 448         if (GSS_ERROR(maj_stat)) {
 449             if (d->context_hdl != GSS_C_NO_CONTEXT)
 450                 gss_delete_sec_context (&min_stat,
 451                                         &d->context_hdl,
 452                                         GSS_C_NO_BUFFER);
 453             break;
 454         }
 455         if (maj_stat & GSS_S_CONTINUE_NEEDED) {
 456             p = strstr(reply_string, "ADAT=");
 457             if(p == NULL){
 458                 printf("Error: expected ADAT in reply. got: %s\n",
 459                        reply_string);
 460                 if (bindings != GSS_C_NO_CHANNEL_BINDINGS)
 461                     free(bindings);
 462                 return AUTH_ERROR;
 463             } else {
 464                 p+=5;
 465                 input.value = malloc(strlen(p));
 466                 input.length = base64_decode(p, input.value);
 467             }
 468         } else {
 469             if(code != 235) {
 470                 printf("Unrecognized response code: %d\n", code);
 471                 if (bindings != GSS_C_NO_CHANNEL_BINDINGS)
 472                     free(bindings);
 473                 return AUTH_ERROR;
 474             }
 475             context_established = 1;
 476         }
 477     }
 478
 479     gss_release_name(&min_stat, &target_name);
 480
 481     if (bindings != GSS_C_NO_CHANNEL_BINDINGS)
 482         free(bindings);
 483     if (input.value)
 484         free(input.value);
 485
 486     {
 487         gss_name_t targ_name;
 488
 489         maj_stat = gss_inquire_context(&min_stat,
 490                                        d->context_hdl,
 491                                        NULL,
 492                                        &targ_name,
 493                                        NULL,
 494                                        NULL,
 495                                        NULL,
 496                                        NULL,
 497                                        NULL);
 498         if (GSS_ERROR(maj_stat) == 0) {
 499             gss_buffer_desc name;
 500             maj_stat = gss_display_name (&min_stat,
 501                                          targ_name,
 502                                          &name,
 503                                          NULL);
 504             if (GSS_ERROR(maj_stat) == 0) {
 505                 printf("Authenticated to <%s>\n", (char *)name.value);
 506                 gss_release_buffer(&min_stat, &name);
 507             }
 508             gss_release_name(&min_stat, &targ_name);
 509         } else
 510             printf("Failed to get gss name of peer.\n");
 511     }
 512
 513
 514     return AUTH_OK;
 515 }
 516
 517 struct sec_client_mech gss_client_mech = {
 518     "GSSAPI",
 519     sizeof(struct gss_data),
 520     gss_init,
 521     gss_auth,
 522     NULL, /* end */
 523     gss_check_prot,
 524     gss_overhead,
 525     gss_encode,
 526     gss_decode,
 527 };
 528
 529 #endif /* FTP_SERVER */